An organic light emitting phenomenon denotes a phenomenon where electrical energy is converted into light energy by using an organic material. That is, in a case where an organic material layer is disposed between an anode and a cathode, when a voltage is applied between the anode and the cathode, the anode injects a hole into the organic material layer, and the cathode injects an electron into the organic material layer. The hole and the electron which are injected into the organic material layer are combined to generate an exciton, and when the exciton is shifted to a ground state, light is emitted.
A lighting device using an organic light emitting device has a structure where a voltage is applied by a terminal disposed in a border. However, as a current applied to the border flows to a center portion of an emissive area, voltage drop occurs due to an internal resistance.
Due to the voltage drop, luminance non-uniformity occurs between emissive areas. For this reason, an area of the lighting device increases, or a ratio difference occurs between a widthwise side and a lengthwise side of the lighting device occurs. Consequently, if an operating current value increases, the luminance non-uniformity becomes more severe.
Therefore, it is required to develop an organic light emitting device that emits light having uniform luminance by solving luminance non-uniformity between emissive areas.